From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
List of specifications and modifications for clutch and pedal components.
| Identifier | ExFiles\Box 85\2\ scan0298 | |
| Date | 16th November 1936 | |
| -9- Rm{William Robotham - Chief Engineer}/Smth.39/AP.16.11.36. G.B.1.V. When in France had 11" clutch, No.6. facings, stronger springs. N.Sch.4776 pedals with Rm.{William Robotham - Chief Engineer}159 operating lever giving 15% reduction in pedal pressure. B.23.AE. No.6. facings, stronger springs, N.Sch.4776 pedals. B.56.WH. Stronger springs, No.6. facings on R.R. type plate. Rm.{William Robotham - Chief Engineer}173. Rm{William Robotham - Chief Engineer}/Smth. | ||